Device for shooting pins and bolts



t is Nov. 20, 1956 M. SKUMAWITZ 2,771,607

DEVICE FOR SHOOTING PINS AND BOLTS Filed Oct. 16, 1953 -1mm I 1 i INVENTOR: MAX .SKUMAWITZ,

BY M 4M Hi5 AGE/vb:

United States Patent'O DEVICE FOR SHOOTING PINS AND BOLTS Max Skumawitz, Tiefenbroich, near Ratingen, Germany,

assignor to Bossong-Werk G. in. b. H., Lintorf, Germany Application October 16, 1953, Serial No. 386,643 Claims priority, application Germany October 25 1952 3 Claims. (Cl. 144.5)

April 5, 1955, for a Gun for Fastener Projectile assigned to Bossong-Werk G. In. b. H. of Germany and to copending patent application of Alexander Hoif-mann, Serial No. 383,037, filed September 29, 1953 for an Impact Gun, and now abandoned, also assigned to Bossong- Werk G. m. b. H. of Germany.

In the known impact guns of the above noted type the barrel is axially displaceable in a chamber and subjected to the action of a propulsion spring. The impact guns must be firmly pressed onto the materials into which the pin is propelled whereupon the gun barrel is pushed back and the cartridge inserted into the rear end of the gun is fired.

A great disadvantage arises insofar as a strong repulsive action is created upon the release of the shot the pressure waves produced in front of the pin and the propelling gases produced at the rear thereof escape laterally from the barrel during the insertion of the pin or bolt. As a consequence thereof the gun is prematurely lifted from its operating place; its manipulation is thereby rendered diflicult and frequent accidents are caused accordingly.

It is the main object of the invention to provide an impact gun, where the recited drawbacks are eliminated and the gun during the shooting of the pin securely rests upon the operating place.

This object is realized in conformity with the invention by the provision of a pressure releasing chamber surrounding the front portion of the gun barrel and acting as a recoil buffer. This pressure releasing chamber is p-re-ferably formed by a sleeve applied to and surrounding the front end of the gun barrel with a certain distance therebetween to create said chamber; the sleeve is provided with a front flange cooperating with gas exit channels the latter being so located in said front flange that in the advanced position of the barrel the front portion of the sleeve is located in the rear and in its rearward position is located in front of the gas exits from said channels.

In this manner the bolt propelling pressure gases which accumulate in front and in the rear of the bolt may escape through lateral channels into an expansion or pressure release chamber, whereby they hit the front flange of the sleeve which is solidly connected with the gun casing, and

counteract the repulsion forces, which are exerted upon the parts of the gun which lock the cartridge chamber. Simultaneouslyand this is a further important advantage of the instant gunthe major portion of the propelling gases is caught in the pressure release chamber, whereby a lateral escape of the gases at the barrel end during or immediately upon the shooting of the pin is practically eliminated.

2,771,607 Patented Nov. 20, 1956 The invention will now be described more in detail and with reference to the accompanying drawings, wherein:

Fig. 1 is a longitudinal vertical section of the front portion of the gun, and

Fig. 2 is a similar sectional view showing the casing and sleeve in their advanced position relative to the muzzle of the barrel.

The gun forming the subject matter of this invention essentially comprises a cylindrical casing 1 axially displaceable with respect to a barrel 3, a recoil spring 2 being arranged between the casing 1 and the barrel 3. The barrel 3 has a rear portion surrounded by the spring 2, a middle portion and a front portion being in the position shown in Fig. 1 outside the sleeve 5 moved to the front portion of the casing 1.

The device is provided with a customary equipment, not shown, to actuate the gun; a hole 4 serves to receive the means connecting the gun with its operating parts, as described in the above referred-to prior copending patent applications.

In conformity with the invent-ion a sleeve 5 is screwed onto the front part of the casing 1; this sleeve 5 surrounds the front portion of barrel 3 and is provided with a frontal flange 6 supported upon the front portion 3 of the barrel. Inwardly inclined gas channels 7 are provided in this front port-ion 3 gas exit openings 8 leading from the channels 7 are connected with each other by a recess 9 applied to the periphery of said barrel 3. The channels 7 and the recess 9 are so positioned that flange 6 is in the advance position of the barrel 3, see Fig. 1, located in the rear of the recess 9 and of the gas exits 8; in the rearward position of the barrel 3 shown in Fig. 2 the flange 6 is located in front of said recess 9 and said gas exits 8. A buffer spring 12 is located between an inner abutment 10 pro-- vided in barrel 3 and an inner abutment 1 1 provided in sleeve 5.

A cartridge container 13 is located at the rear end of easing 1 and of sleeve -5 connected therewith.

The barrel 3 has under normal conditions the position shown in Fig. 1, whereby the barrel end 14 projects with its annular recess 9 beyond the sleeve 5.

In order to shoot the bolt into the solid material aggregate, for instance a wall, the device is set with its end 14 upon the objective and the casing 1 and sleeve 5 are moved to their forward position (Fig. 2) against the action of the recoil spring 2, whereby the fuse cap (not shown) of a cartridge being present in the container or chamber 13 enters into the reactive sphere of a firing bolt.

In this position of the barrel 3 the longitudinal bore 15 thereof is connected with a gas pressure release chamber 16 formed by the sleeve 5 and the front portion of the barrel 3 through channels 7 and recess 9, said chambers acting as a recoil butter.

Upon release of the shot the produced pressure waves as well as the driving gases flow through channel 7 into the pressure release chamber 16, whereby they hit flange 6 of sleeve 5 and are forwardly deflected. As a consequence thereof the pressure waves as well as the driving gases may expand prior to their entrance into the barrel mouth; their lateral flow from the barrel mouth is therefore practically eliminated.

The greater part of the recoil exerted by the driving gas-es upon the closure means for the cartridge chamber 13 is practically eliminated since these means, as generally known, are operative in cooperation with the rearwardly located gun locking means.

Upon the firing of the gun and removal of the same from the shooting spot the casing 1 and sleeve 5 are moved by means of spring 2 to their retracted position, this retracted movement being arrested by spring 12. The

driving gases enclosed in release chamber 1 6 may escape through channel 7 and boreIS.

Since certain changes may be made in the above article and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

Having thus described the invention, what i claim as new and desire to be secured by Letters Patent, is as follows:

1. A device for shooting pins and bolts into solid material aggregates, such as concrete and stone walls, comprising, in combination, an outer casing, a barrel having a rear portion, a middle portion and a front portion, said casing being axially displaceable with respect to said barrel, an abutment forming part of said barrel, a recoil spring located between said abutment of said barrel and the end wall of said casing so as to hold in the expanded position of said recoil spring said barrel and said casing in a relative position wherein said middle and front portions of said barrel protrude beyond said casing, a sleeve connected to the front portion of said casing and surrounding said middle portion of said barrel, said sleeve forming a gas release chamber surrounding said middle portion of said barrel so as to act as a recoil buffer, and a flange forming the front end of said sleeve, said barrel having a longitudinal bore connected with gas exit openings arranged between said front and middle portions of said barrel, said flange cooperating .with said gas exit openings arranged between-said front and middle portions of said barrel so that in said expanded position of said recoil spring said barrel protrudes with said gas exit openings beyond said flange arranged at the front end of said sleeve whereas when said recoil spring is compressed said openings communicate with said gas release chamber formed inside said sleeve.

2. A device as claimed in claim 1, and an angular recess provided in said barrel and separating said front portion from said middle portion, said angular recess being located outside said sleeve and said frontal flange, when said recoil spring is in expanded condition, said angular recess being inside said sleeve when said recoil spring is in compressed condition.

3. A device as claimed in claim 1, said sleeve having an abutment surrounding said middle portion of said barrel, an abutment on a rear portion of said barrel engaging said recoil spring, and a buffer spring surrounding said middle portion of said barrel and abutting against said abutments of said sleeve and said barrel.

References Cited in the file of this patent UNITED STATES PATENTS 2,504,311 Dunn Apr. 18, 1950 2,518,395 Sopris Aug. 8, 1950 FOREIGN PATENTS 283,155 Switzerland Sept. 16, 1952 

